Fishing spearguns have not changed dramatically over the last century in that they continue to enjoy spearpoint shafts that are biased into a trigger release mechanism by a plurality of rubber bands, and a string line is provided for retrieving the spearpoint and shaft after firing.
Of course, modern manufacturing techniques have made improvements which have somewhat affected the appearance of the speargun, its safety and ease of cocking and trigger pull. For example, the grip assembly now includes, in one case, a one-piece plastic housing that forms the handle grip, the trigger guard, the butt support, the forepiece support and the housing for the trigger assembly.
The trigger assembly has been improved by providing it with a removable frame that permits the trigger assembly to be easily removed from the grip housing. This prior trigger assembly includes a one-piece plastic frame having an upper spearpoint shaft guide and spaced parallel lower frames that pivotally support both the trigger and a shaft latching bar.
The trigger assembly is also provided with a safety pawl operated by a knob on the outside of the grip housing.
Since these spearguns have remained basically unchanged, performance improvements, although they may appear small, contribute greatly to the popularity of the speargun in this fascinating, competitive and still somewhat esoteric sport.
In these prior trigger assemblies, the latch bar and the trigger slidably engage one another and are constructed of the same material and after a period of use, the interengaging surfaces become scored causing trigger pull to become erratic which results in a jerking movement of the gun during firing throwing the spear off target.
Another problem in these prior trigger assemblies is that the safety mechanism requires the use of the fisherman's other hand, or more particularly, with the fisherman's left hand on the grip housing handle, he either has to operate the safety release with his right hand or take his left hand off the grip to release it.
In my U.S. Pat. No. 4,962,747, issued Oct. 16, 1990, I disclose and describe a speargun that includes a trigger assembly that has a left-right reversible safety operable with the trigger hand while on the grip, and an improved trigger pull achieved by engaging bearing surfaces on the latch bar and trigger.
That speargun was provided with a one-piece grip housing in the general shape of the housing of an automatic pistol that has an upper slot into which a trigger assembly is insertable. The trigger assembly has a plastic frame with an integral top tube that receives the proximal end of the spearpoint shaft, and parallel spaced depending walls that pivotally support the trigger, the latch bar, and a safety pawl.
The latch bar has an upwardly projecting shaft locking pawl substantially in line with the pivotal axis of the locking pawl, and this location has the effect of reducing the outward shaft torque on the latch bar, and hence the trigger, reducing trigger pull effort by at least 32%.
The latch bar has an elongated arm that rests on a shoulder on the trigger in the set or firing position. The latch bar is constructed of hardened 17-7 stainless steel, while the trigger is constructed of 302 stainless, or equivalents thereof, resulting in a significant difference in hardness and creating a bearing effect between the latch bar arm and the trigger shoulder eliminating the prior problem of scoring on these surfaces and thereby smoothing out trigger pull substantially.
The safety pawl is operated by a knob and shaft assembly projecting through the grip housing and the trigger frame. The knob has a radially extending finger that is positioned so that when the safety is "on" with the latch bar holding the spearpoint shaft in a firing position, this finger depends over the trigger blocking movement of the fisherman's index finger toward the trigger. This is important in spearguns because underwater conditions make it difficult to visually observe whether the safety is "on" or "off".
After recognizing a safety "on" condition, the fisherman, with his trigger hand on the housing grip, releases the safety with this index finger of his trigger hand by rotating the knob finger clockwise toward a horizontal position away from the trigger, rotating the safety pawl away from the trigger creating a firing condition.
The safety knob and shaft assembly is insertable through the safety pawl from either the right or left side of the grip housing permitting the safety to be used with the trigger hand on the grip for both right or left side spear fishermen.
While my prior speargun has worked well and been extremely successful, it does have several disadvantages that are addressed in the design of the speargun according to the present invention.
Firstly, the safety assembly is journaled in the frame of the removable trigger assembly, and since the width of the frame is fairly narrow, the shaft supporting the safety assembly tends to rock somewhat during use, creating a feeling of uncertainty in operation. And oxidation caused by salt water and foreign matter in my prior gun had a deleterious effect on the metal bearings. This prior safety assembly also includes a spring for urging the safety assembly to its appropriate axial position. The spring is mounted externally of the grip housing, which requires the safety assembly shaft to project a significant distance from the grip housing. This design has resulted in some cases in the safety assembly shaft bending which sometimes prompts the spear fisherman to completely remove the safety assembly.
My prior speargun also included a line holding and release assembly mounted in the grip housing that included a shaft with an hexagonal head, a torsion spring, and a finger bar. The torsion spring was seated at one end in the hexagonal shaft head, and the other end seated in the line holding finger bar. As these parts are assembled to the grip housing, it was necessary to rotate the hexagonal head to tension the spring prior to pushing the head into a mating hexagonal hole in the grip housing. This was an extremely difficult assembly procedure that required repetitive attempts to locate the parts properly and at the same time rotate the head to tension the finger bar. Also in this design the spring was carried by the shaft inside the housing, without any support during initial assembly, and tended to push the shaft out of the housing sometimes causing these parts to be lost.
The third problem with my prior speargun, as well as all of the spearguns that I am aware of, is the necessity for the spearpoint shaft to be threaded completely through the muzzle both when loading the spearpoint shaft and when removing the spearpoint shaft from the gun after an incomplete fire when the spearpoint shaft fails to clear the muzzle.
It is a primary object of the present invention to ameliorate these problems noted above both in the prior art and in my prior speargun, as shown and described in my U.S. Pat. No. 4,962,747, issued Oct. 16, 1990.